User's manual for RESRAD version 6.

Abstract

In 1993, a manual on using Version 5 of the RESRAD code to implement the U.S. Department of Energy's (DOE's) residual radioactive material guidelines was released. Since then, as part of the RESRAD quality assurance (QA) program, the RESRAD code has undergone extensive review, benchmarking, verification, and validation. The manual and code have been used widely by DOE and its contractors, the U.S. Nuclear Regulatory Commission, U.S. Environmental Protection Agency (EPA), U.S. Army Corps of Engineers, industrial firms, universities, and foreign government agencies and institutions. New features, some in response to comments received from users, have been incorporated into the code to form RESRAD 6. These improvements have increased RESRAD's capabilities and flexibility and enabled users to interact with the code more easily. With the improvements, the code has become more realistic in terms of the models and default parameters it uses. RESRAD 6 represents the sixth major version of the RESRAD code since it was first issued in 1989. The RESRAD code can now perform uncertainty/probabilistic analyses with an improved probabilistic interface. 1 It uses a preprocessor and a postprocessor to perform probabilistic dose and risk analyses. 2 It incorporates default parameter distributions (based on national average data) for selected parameters. The code can provide analysis results as text reports, interactive output, and graphic output. The results of an uncertainty analysis can be used as a basis for determining the costeffectiveness of obtaining additional information or data on input parameters (variables). 3 The RESRAD code now allows users to calculate the time-integrated dose and risk at userspecified times. The instantaneous dose/risk can be calculated by setting the time integration point to one. The other major changes in the code are a new external exposure model, new area factor xii model for the inhalation pathway, and New Dose Conversion Factor (DCF) Editor. The DCF Editor gives users the ability to change dose conversion factors, transfer factors, and slope factors. Moreover, the RESRAD database was updated. It now includes inhalation and ingestion dose conversion factors from the EPA's Federal Guidance Report No. 11 (FGR-11), direct external exposure dose conversion factors from FGR-12, risk slope factors primarily from the latest health effects and summary tables, and radionuclide half-lives from International Commission on Radiological Protection Publication 38. The risk coefficients from FGR-13 are also available in the code. Version 6 of RESRAD incorporates many improvements made since Version 5 was released. These include the addition of seven new radionuclides: selenium-79, zirconium-93, neodymium-93m, barium-133, curium-245, curium-246, and curium-247. The code was also modified to account for radioactive decay and ingrowth during food storage times. The code now has an improved groundwater model to ensure convergence for K d calculations when water concentrations are known; has an improved radon pa...

Corrective Action Investigation Plan for Corrective Action Unit 570: Area 9 Yucca Flat Atmospheric Test Sites Nevada National Security Site, Nevada, Revision 0

“…External dose is determined directly from TLD measurements. Internal dose is determined by comparing analytical results from soil samples to RRMGs that were established using the RESRAD computer code (Yu et al, 2001). RRMGs are radionuclide-specific values for radioactivity in surface soils.…”

Corrective Action Decision Document/Closure Report for Corrective Action Unit 504: 16a-Tunnel Muckpile, Nevada Test Site

“…bgs = Inches below ground surface mg/kg = Milligrams per kilogram None of the radionuclides found in the Contaminated Area soils exceeded the PALs as defined in the CAIP (DTRA, 2001) except for Cs-137, so the PALs for those radionuclides are identified as the FALs. For Cs-137, which exceeded the PAL, an SSTL was calculated using the RESRAD computer code (Yu et at., 2001). The SSTL then became the FAL for that constituent.…”

“…The Tier 2 evaluation for the radionuclides was conducted by entering site-specific radionuclide information and physical characteristics of the site into the RESRAD program (Yu et at., 2001) to calculate the site-specific action levels. This calculated the site-specific minimum activities needed to sum to an exposure dose of 25 millirem per year (mrem/yr) to a site receptor.…”

“…A more detailed discussion of the radionuclides and the determination of the FALs is provided in Appendix D. (NCRP, 1999) scaled from 25-to 15-millirem-per-year dose and the generic guidelines for residual concentration of radionuclides in DOE Order 5400.5 (DOE, 1993). Final action level based on RESRAD calculation (Yu et al, 2001) for remote scenario.…”

Methodology for Exposure and Risk Assessment in Complex Environmental Pollution Situations

“…Radium-226 concentration measured in leafy vegetables (C veg ) was 21,9 Bq/kg (Falcão et al, 2005); vegetation ingestion rate (U veg,ing ) was set to 0,175 kg/d (Yu, 2001); risk coefficient for foodstuff ingestion (RC food,ing ) was considered to be 1,38919 x 10 -8 Bq -1 (EPA, 1995); exposure frequency (E f ) was set to 365 days per year, as previously, and the fraction of ingested leafy vegetables from the farm products (f veg ) was set to 1 (all leafy vegetables consumption comes from the farm and are contaminated). The cancer risk incurred by contaminated leafy vegetables ingestion is 1,94 x 10 -5 .…”